How would you describe the narrator's mental and psychological condition? Why does the writer use alliteration in the title ?

The narrator is clearly suffering a psychological breakdown in the story. I mean, he is relating how he murdered an old man for no reason other than his eye creeped him out, essentially. Since he tells the story in first-person, the reader cannot determine how much of what he says is true; thus, he is an unreliable narrator. He also repeatedly tells us that he is perfectly sane, & goes to great lengths to convince us of that. Yet he is clearly describing the actions of a madman. This is evident from first line of the story: ‘‘True—nervous—very, very dreadfully nervous I had been and am; but why will you say that I am mad?'' We quickly realize that the reason someone would say that is because he is insane.

As far as the alliteration in the title, it has a few different purposes. One is for remembering: phrases tend to stick in your head if they use alliteration. However, it also creates a rhythm to the title, almost like the beating of a heart. Read it with emphasis on the "T" sounds; you'll hear a beat very similar to what the narrator imagines coming through his floorboards.